Blackburn Cirrus Major
The Blackburn Cirrus Major is a British, inline-four aircraft engine which was developed in the late 1930s, but continued development and production into the 1940s and post war. == Design and development == The Blackburn Cirrus Major started life as a clean-sheet replacement for the original 1920s Cirrus and Hermes series of upright inline four-cylinder air cooled aircraft engines originally designed by Frank Halford for the early DH60 de Havilland Cirrus Moth and which had been in production by the Aircraft Disposal Company (ADC) and later Cirrus Aero Engine Limited, which itself evolved into the Cirrus-Hermes Engineering Company.